Accuphase P-102
¥ 235,000 (released in January 1987)
Commentary
This is a class A stereo power amplifier that adopts a fully balanced push-pull system.
Balanced transmission is applied to all systems from input to output, enabling high-quality power transmission.
In the balanced transmission method, a dedicated transmission system is installed for each of the plus and minus signals. In principle, this system cancels the external noise and at the same time cancels the distortion generated by the amplifier, so that the pure signal component can be extracted.
Class A drive system is adopted, and the input stage and output stage are class A operated.
The output stage is composed of parallel push-pull transistors for high-band power amplification with collector loss Pc = 80W. The total Pc of the unit amplifier on one side is 320W, realizing an output stage with a margin.
The output stage can withstand low impedance loads by providing a margin, and the pre-drive stage employs a power MOS FET drive, an original Accu-Phase system, to achieve an ideal drive.
Class A cascode differential push-pull is adopted for the input stage.
Because the cascode circuit is used for high frequency amplification, operation is stable over a wide frequency band, input linearity is good, and a wide dynamic range is secured.
The power supply section is completely independent on the left and right sides, and uses a twin mono configuration with two complete monophonic amplifiers.
This eliminates the interaction between left and right.
A direct connection method is used for input.
The AcPHASE original DC servo system is adopted to prevent damage to the speakers caused by amplification of pre-amplifiers with large DC drift when connected. In addition to cutting DC, the DC drift of the amplifier itself due to temperature change is also stabilized.
Both balanced and unbalanced inputs are used.
Equipped with an analog type large meter. The output meter indicates the peak value with a pointer type meter that can directly read dB and output watt. The logarithmic compression allows direct reading of a wide power range.
It also has a built-in switch to turn off the meter and turn off the indicator.
It is designed with a natural Persimmon side board attached to the panel finish of gold-like scratch hairline.
Model Rating
Type | Stereo power amplifier | ||||
Rated output (both channel operation 20 Hz to 20 kHz, Distortion Factor 0.02%) |
2 Ω load : 70W/ch 4 Ω load : 80W/ch 8 Ω load : 50W/ch 16 Ω load : 25W/ch |
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Total harmonic distortion factor (20 Hz to 20 kHz, both channel operation) |
2 ~ 4 Ω Load : 0.02% 8 ~ 16 Ω load : 0.01% |
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IM distortion factor | 0.003% | ||||
Frequency characteristic |
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Gain | 28.0dB | ||||
Load impedance | 2 Ω ~ 16 Ω | ||||
Damping factor | 70 | ||||
Input sensitivity (8 Ω load) | Continuous average output : 0.8 V 0.11 V at 1W output |
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Input impedance | Equilibrium : 40k Ω Unbalanced : 20k Ω |
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S/N ratio (A-corrected) |
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Output meter | Logarithmic compression type, -40dB to + 3 dB and output direct reading scale | ||||
Semiconductor used | Transistor : 81 FET : 16 IC : 8 Diode : 89 pcs |
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Pwer | 100V/117V/220V/240V, 50Hz/60Hz | ||||
Power consumption | No input : 245W Electrical Appliance and Material Control Law : 255W 8 Ω load rated output : 300W |
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External dimensions | Width 475x Height 170x Depth 408 mm | ||||
Weight | 22kg |